Techniques are disclosed for systems and methods to provide accurate, low lag, and reliable autopilot autorelease in a hydraulic steering system for mobile structures. A hydraulic steering system includes a logic device configured to communicate with an autopilot pump controller, a control surface reference sensor, an orientation sensor, and/or a gyroscope. Control and sensor signals provided by the pump controller and/or the various sensors are used to selectively enable and/or disable an autopilot release signal. The autopilot release signal enables or disables the autopilot pump controller and/or an autopilot pump, or controls the autopilot pump controller to enable or disable the autopilot pump.

A force sensing element is used in a pressure transducer. The force sensing element includes a flat, disc-type spring having a unitary body that circumscribes a central axis, and a plurality of spirals that are continuous with each other and extend radially outwardly from the central axis. The plurality of spirals includes nested symmetrical flights having walls with a non-uniform thickness, and the disc spring is uniformly deflectable along the central axis in response to force acting on the disc-type spring. The spring is configured to have a high accuracy and a high fatigue life such that the spring is suitable for use in high-pressure applications that may require repeatability while operating with over 10 million cycles of unidirectional or bi-directional axial loading.

An actuator system includes an actuator which is configured to generate a loading on a control surface, as a function of an actuation order received, a command unit of the actuator, which is configured to compute an actuation order of the actuator, a reception element for receiving a current value of the loading generated by the actuator, and a limitation unit configured to reduce the control authority of the command unit as a function of the current value of the loading and to limit the loading of the actuator to a predetermined setpoint value.

In some embodiments, an actuation system includes a an actuator assembly, a yoke, and a control rod. The actuator assembly comprises a first actuator. The first actuator is configured to extend in a first direction and retract in a second direction opposite of the first direction. The yoke is coupled to the first actuator at a first actuator end proximate to the first direction. The control rod is coupled to the yoke at a first control rod end and extends in the second direction past the actuator assembly to a second end in mechanical communication with an output device.

An aircraft comprises an aircraft structure, a flight control surface attached to the aircraft structure, and a local hydraulic power pack disposed proximal to the flight control surface. The local hydraulic power pack is configured to provide pressurized hydraulic fluid for actuating the flight control surface. The local hydraulic power pack comprises a reservoir for the hydraulic fluid and two hydraulic pumps for pressurizing the hydraulic fluid.

A SCAS module includes one or more SCAS actuators wherein each SCAS actuator comprises a piston arranged for linear motion within a hydraulic chamber in response to a flow of hydraulic fluid metered by a valve. The piston comprises a flexible rod or quill for providing a linear output along the first axis, the flexible rod or quill being mounted internally within an annular portion of the piston so that a space is defined around the flexible rod or quill. The flexible rod or quill is capable of deforming into the surrounding space in order to accommodate movement of the flexible rod or quill.

A system and method for controlling two or more actuators acting together to move a component or surface includes Two or more actuators engaged with the component or surface to be moved. Each actuator is displaceable to move the component or surface in response to a component or surface position command. Each actuator has an associated actuator controller to receive the position command and to output an actuator displacement command. The system also includes force fight control means configured to determine a force differential from forces, or a pressure differential from pressures measured at each actuator and to derive a speed and/or a current offset signal, and to provide the offset signal to the actuator controllers to modify the actuator displacement commands.

A hydraulic actuator system includes a hydraulic actuator having a housing with a piston having a piston shaft arranged within the housing. The housing is formed to have first, second and third regions, wherein the first region is between the second and third regions and has a larger major dimension than the second and third regions. The system also includes first, second, and third piston heads connected to the piston shaft with the first piston head being tween the second and third piston, wherein the first position head is within the first region and divides the first region into two volumes, the second piston head is in the second region and defines a first volume and the third piston head is in the third region and defines a fourth volume. The system also includes a mode selection device operably connected to the first, second, third and fourth volume.

An electrohydrostatic actuator, comprising an actuator for driving a component, a pump configured to pump hydraulic fluid for operation of the actuator, and a control valve for controlling passage of the hydraulic fluid between the actuator and the pump, wherein the control valve is movable between first and second positions. In the first position the control valve is configured to convey hydraulic fluid from the pump through the control valve for operation of the actuator, and in the second position the control valve is configured to fluidly disconnect the pump and the actuator, and circulate hydraulic fluid arriving from the pump back to the pump via a first constriction within the control valve.

An actuation system for resolving the effects of force-fight between multiple stages within an actuator coupled to an aircraft flight control member includes a yoke configured for connection to the flight control member, a first actuator operatively coupled to the yoke, and a second actuator and a third actuator operatively coupled to the yoke, the second and third actuators symmetrically arranged on opposite sides of the first actuator. A first control member is operatively coupled to the first actuator, and a second control member is operatively coupled to the second actuator and the third actuator. The second control member is configured to operate independent of the first control member to effect motion of the flight control member.